Ganesh
Chaturthi is one of the most popular festival. This is the birthday
of God Ganesha. It falls on the 4th day of the
bright fortnight of Bhadrapada (August-September).
It is observed throughout India, as well as by devoted in all
parts of the world.

Ganpati is the elephant-headed God. He is worshipped first in
any prayers. His names are repeated first before any auspicious
work is begun, before any kind of worship is begun. He is the
God of power and wisdom. He is the eldest son of Shiva and the
brother of Skanda or Kartikeya. He is the energy of Shiva and
so he is called the son of Shankar and Parvati.

Each
of the Puranas has a different story regarding the birth of Lord
Ganesh. In some he is the manasika putra (mind-born son) of Lord
Shiva. In others he is the creation of Parvati. In still others
he is the son of Shiva and Parvati.

The most popular legend deals with the birth of Lord Ganesh to
Parvati. Once while Parvati was going for her bath, she rubbed
off the dust and oil from her body and out of it created the figure
of a young boy. She infused life into the figure and told him
he was her son and should guard the entrance when she went to
bath.
Soon after, Shiva came to see Parvati but the young boy blocked
his way and would not let him in. Shiva, unaware that this lad
was his son, became furious and in great anger fought with the
boy whose head got severed from his body in the ensuing battle.

Parvati, returning from her bath, saw her headless son, and in
aggrieved anguish threatened to destroy the heavens and earth.

The gods and Shiva pacified her and the latter sent out his ganas,
or hordes, to bring the head of the first living being with his
head towards the north (the auspicious direction associated with
wisdom). The first living creature they found sleeping with his
head to the north was an elephant. They brought the head of this
animal and Shiva placed it on the trunk of Parvati's son and breathed
life into him.

Parvati was overjoyed and embraced her son, the elephant-headed
boy whom Shiva named Ganesh, the lord of his ganas “
Ganpati”